The present invention relates to a sander including a main body provided with a motor, and a base which is disposed below the main body and makes orbital motion according to rotation of the motor.
In a sander, an output shaft is projected to the lower side of the main body having a motor, and the base is eccentrically joined to the output shaft to cause the base to make an orbital motion (eccentric motion) according to rotation of the output shaft in response to driving of the motor, and an object material can be sanded with a sanding paper stretched on the bottom surface of the base. Between the main body and the base, to prevent vibrations (in particular, vertical flopping) according to rotation restriction and orbital motion of the base, receptacles are formed on the main body and the base, respectively, so as to face each other, and between the receptacles, feet are laid. The feet are integrally molded from an elastic material such as rubber in many cases, however, its durability lowers due to heating and wearing. In order to solve this problem, Japanese Patent No. 3634995 discloses a foot including a metallic foot body and elastic members (for example, an O-ring). The elastic members are disposed in the receptacles to support upper and lower ends in the axial direction of the foot body.
On the other hand, when such a foot is used, dust enters the gap, etc., between the receptacle and the O-ring and may wear the O-ring, foot, and receptacle. In order to solve this problem, Japanese Utility Model Publication No. 51-3988U teaches to provide a flexible dustproof cover so as to cover the entire region for providing the foot between the main body and the base.
However, the above-described dustproof cover is made of a thin flexible material which has almost no rigidity, so that its upper and lower ends must be attached by screws, etc., to the opposing surfaces of the main body and the base, respectively. In addition, if gaps are left on the attaching portions, dust may enter from these portions. Therefore, to maintain the sealing performance of the attaching portions, flat attaching surfaces must be provided on the main body and the base, and this limits the shapes of the main body and the base.